1. Field of the Invention
The present invention relates to a method of controlling the pH of a solution using a microfluidic device including an electrolysis device.
2. Description of the Related Art
Microfluidic devices refer to devices in which an inlet, an outlet, a reaction chamber, etc., are interconnected through microchannels. Such devices are widely known in the field and are used in micro-analytic devices, such as a lab-on-a-chip (LOC). In addition to microchannels, a micropump for inducing the flow of fluid, a micromixer for mixing fluids, a microfilter for filtering a fluid, etc., are included in microfluidic devices.
A microfluidic device used as a biological analytic device, such as a LOC, performs a series of biological analytic processes, such as cytolysis, nucleic acid amplification and separation, such as polymerase chain reaction (PCR), and protein separation and detection. A conventional pH control process involved in such biological analysis processes is achieved by adding or removing an acidic solution, a neutral solution, or a buffer solution. However, when adding or removing a pH-adjusting solution in a microfluidic device, problems associated with dilution, mixing and the flow of a substance in a microchannel may arise because a small amount of sample is used. Furthermore, the added pH-adjusting material may inhibit subsequent biological analysis processes. In this case, the pH-adjusting material has to be removed.
However, a method of controlling pH in-situ while generating hydrogen ions and hydroxide ions through electrolysis and mixing the ions is still not disclosed.
However, the inventors of the present invention found a method of controlling pH using electrolysis in a microfluidic device, in which the volume ratio of anode and cathode chambers is controlled, and solutions generated in the anode and cathode chambers through electrolysis are mixed in the equal volumes, and completed the prevent invention.